This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Sox2, as well as many other transcription factors, are known to be O-GlcNAcylated. In order to better understand O-GlcNAcylation during pluripotency maintenance, one must be able to i) identify the low abudnace O-GlcNAcylated nuclear proteins involved without bias, ii) assign site-specific residues for O-GlcNAcylation and iii) understand from what cellular context the O-GlcNAc signal came, since many nuclear events come from extranuclear signals.